1,537 research outputs found
A model-based approach to correcting spectral irradiance data using an upward-looking airborne sensor (CASI ILS)
A number of aircraft sensors have the facility to measure spectral downwelling irradiance using a sensor mounted on the roof of the aircraft, but these data are rarely used for atmospheric correction. Part of the problem is that the attitude of the airborne platform is always changing during flight, even in stable conditions, so that direct use of data from an incident light sensor (ILS) can introduce errors into atmospheric correction methods. The continual motion of the ILS is used here to advantage, as a means to fit a sky radiance distribution model developed by Brunger and Hooper (1993) to data from the Itres Instruments CASI ILS. The inclination of the ILS sensor, due to changing aircraft attitude, is considered as
the slope plane in the model. The selected model coefficients correspond to parameterised atmospheric conditions and represent atmospheric transmission and the proportion of direct:diffuse flux. The method was used to correct CASI ILS data acquired over a site in southern England. Comparison with spectral irradiance measured simultaneously on the ground shows that the method reduced the variability of the ILS data and also compensated for the effect of different flight directions. The sky radiance distribution at sensor level is also calculated by
the model, and shows the characteristics of the sky conditions at the time of each flight
Retrieval of at-sensor irradiance using Incident Light Sensor (ILS)
A number of aircraft sensors have the facility to measure spectral downwelling irradiance using a sensor mounted on the roof of the aircraft, but these data are rarely used for atmospheric correction.
Part of the problem is that the attitude of the airborne platform is always changing during flight, even in stable conditions, so that direct use of data from an incident light sensor (ILS) can introduce errors into atmospheric correction methods.
The continual motion of the ILS is used here to advantage, as a means to fit a sky radiance distribution model developed by Brunger and Hooper (1993) to data from the Itres Instruments CASI ILS. The inclination of the ILS sensor, due to changing aircraft attitude, is considered as the slope plane in the model. The selected model coefficients correspond to parameterised atmospheric conditions, i.e. clearness index and diffuse ratio. The ILS data corrected by the model are wellmatched
to variations of irradiance measured at ground level during three flights. The radiance distribution at sensor level is also calculated by the model, and shows the characteristics of the sky conditions at the time of each flight
Neutrino Oscillations and Collider Test of the R-parity Violating Minimal Supergravity Model
We study the R-parity violating minimal supergravity models accounting for
the observed neutrino masses and mixing, which can be tested in future collider
experiments. The bi-large mixing can be explained by allowing five dominant
tri-linear couplings and . The desired ratio
of the atmospheric and solar neutrino mass-squared differences can be obtained
in a very limited parameter space where the tree-level contribution is tuned to
be suppressed. In this allowed region, we quantify the correlation between the
three neutrino mixing angles and the tri-linear R-parity violating couplings.
Qualitatively, the relations , and are required by the large
atmospheric neutrino mixing angle and the small angle
, and the large solar neutrino mixing angle ,
respectively. Such a prediction on the couplings can be tested in the next
linear colliders by observing the branching ratios of the lightest
supersymmetric particle (LSP). For the stau or the neutralino LSP, the ratio
can be measured
by establishing or , respectively. The
information on the couplings can be drawn by measuring if the neutralino LSP is heavier than the top
quark.Comment: RevTex, 25 pages, 8 eps figure
Anti-inflammatory effect of low intensity ultrasound (LIUS) on complete Freund's adjuvant-induced arthritis synovium
SummaryObjectivesArthritis with intra-articular inflammation was accompanied by joint pain, swelling, and stiffness leading to significant functional impairment. Thus, regulation of joint inflammation is a good therapeutic approach for patients with arthritis. In this study, the effect of low intensity ultrasound (LIUS) applied to an adjuvant-induced arthritic rat model on the synovium was investigated.DesignSynovial inflammation was induced by complete Freund's adjuvant (CFA)-injection into the rat knee joint. LIUS (200 mW/cm2) was applied on the ipsilateral knee everyday for 10 min beginning 1 day after inflammation induction. The expression of proinflammatory factors and immunohistochemical staining pattern of the synovium were assessed.ResultsCFA induced an increase of the knee circumference that was significantly diminished by LIUS. Synovial membrane hyperplasia in the ipsilateral joint was also affected by LIUS. The inflammatory mediators, COX-1/2, IL-1β, and iNOS, but not TNF-α, in the synovial membrane were induced after 3 days, and they closely correlated with the degree of edema. In the synovial membrane, the expression of inflammatory mediators was reduced by LIUS. The chemoattractant chemokine receptor CCR5 also was involved. On immunohistochemical analysis, CFA caused increased infiltration of CD11b-positive cells in the synovium. After 3 days, neutrophils, myeloperoxidase (MPO)-positive cells filled the inflammatory core; later, monocytes and macrophages, ionized calcium binding adaptor molecule 1 (Iba1)-positive cells in the periphery infiltrated the core by day 5. LIUS markedly reduced CFA-induced inflammatory cells infiltration.ConclusionLIUS showed a potent anti-inflammatory effect in this animal arthritis model with reduced infiltration of inflammatory cells into the synovium
Neutrino Mass from R-parity Violation in Split Supersymmetry
We investigate how the observed neutrino data can be accommodated by R-parity
violation in Split Supersymmetry. The atmospheric neutrino mass and mixing are
explained by the bilinear parameters inducing the neutrino-neutralino
mixing as in the usual low-energy supersymmetry. Among various one-loop
corrections, only the quark-squark exchanging diagrams involving the order-one
trilinear couplings can generate the solar neutrino mass
and mixing if the scalar mass is not larger than GeV. This scheme
requires an unpleasant hierarchical structure of the couplings, e.g.,
, and . On the other hand, the model has a distinct collider
signature of the lightest neutralino which can decay only to the final states,
and , arising from the bilinear mixing. Thus, the
measurement of the ratio; would provide a clean probe of the small reactor and
large atmospheric neutrino mixing angles as far as the neutralino mass is
larger than 62 GeV.Comment: 10 pages, 3 figures, version submitted to JHE
Fermion Electric Dipole Moments in Supersymmetric Models with R-parity Violation
We analyze the electron and neutron electric dipole moments induced by
R-parity violating interactions in supersymmetric models. It is pointed out
that dominant contributions can come from one-loop diagrams involving both the
bilinear and trilinear R-parity odd couplings, leading to somewhat severe
constraints on the products of those couplings.Comment: Revtex, 19pp, four figures in axodraw.st
Radiation from accelerated particles in relativistic jets with shocks, shear-flow, and reconnection
We have investigated particle acceleration and shock structure associated
with an unmagnetized relativistic jet propagating into an unmagnetized plasma.
Strong magnetic fields generated in the trailing jet shock lead to transverse
deflection and acceleration of the electrons. We have self-consistently
calculated the radiation from the electrons accelerated in the turbulent
magnetic fields. We find that the synthetic spectra depend on the bulk Lorentz
factor of the jet, the jet temperature, and the strength of the magnetic fields
generated in the shock. We have also begun study of electron acceleration in
the strong magnetic fields generated by kinetic shear (Kelvin-Helmholtz)
instabilities. Our calculated spectra should lead to a better understanding of
the complex time evolution and/or spectral structure from gamma-ray bursts,
relativistic jets, and supernova remnants.Comment: 6 pages, 4 figures, 2012 Fermi Symposium proceedings - eConf C12102
A Detailed Analysis of One-loop Neutrino Masses from the Generic Supersymmetric Standard Model
In the generic supersymmetric standard model which had no global symmetry
enforced by hand, lepton number violation is a natural consequence.
Supersymmetry, hence, can be considered the source of experimentally demanded
beyond standard model properties for the neutrinos. With an efficient
formulation of the model, we perform a comprehensive detailed analysis of all
one-loop contributions to neutrino masses.Comment: 27 pages Revtex, no figur
Time and Amplitude of Afterpulse Measured with a Large Size Photomultiplier Tube
We have studied the afterpulse of a hemispherical photomultiplier tube for an
upcoming reactor neutrino experiment. The timing, the amplitude, and the rate
of the afterpulse for a 10 inch photomultiplier tube were measured with a 400
MHz FADC up to 16 \ms time window after the initial signal generated by an LED
light pulse. The time and amplitude correlation of the afterpulse shows several
distinctive groups. We describe the dependencies of the afterpulse on the
applied high voltage and the amplitude of the main light pulse. The present
data could shed light upon the general mechanism of the afterpulse.Comment: 11 figure
- …